Three ingredients. That is all Cacio e Pepe requires: pasta, Pecorino Romano, and black pepper. And yet this Roman classic has humbled more home cooks than almost any other dish I know. The sauce is notoriously prone to clumping, the pasta can end up gluey, and something about the ratio is always slightly off. After seventeen attempts over two years, I cracked it. Here is everything I know.
The Cheese
Use aged Pecorino Romano — not Parmesan, not a blend. The saltiness and sharpness is essential. Grate it on the finest setting of your box grater (or a Microplane) until it resembles fine powder. This is non-negotiable: coarse cheese will clump and never emulsify properly.
The Pepper
Toast whole black peppercorns in a dry pan until fragrant, then coarsely crack them with a mortar and pestle or the bottom of a heavy pan. The heat of the pan blooms the pepper and removes its rawness; the coarse crack means you get flavour bursts rather than uniform heat.
The Method
Cook your spaghetti or tonnarelli in well-salted but not oversalted water (the cheese is already salty). Toast the cracked pepper in a wide pan with a splash of olive oil. Add a ladleful of starchy pasta water and let it reduce by half. Add the cooked pasta and more pasta water. Remove from heat entirely — this is crucial — and gradually rain in the cheese while tossing constantly, adding splashes of pasta water as needed. The residual heat, the starch, and the fat emulsify into a glossy, creamy sauce that coats every strand. Serve immediately.